4. The hash-code is intended for hashing. This places no verifiable constraint on a conforming implementation, but the intent is that an implementation should make a good-faith effort to produce hash-codes that are well distributed within the range of non-negative fixnums.

5. Computation of the hash-code must terminate, even if the object contains circularities.

Many common hashing needs are satisfied by make-hash-table and the related functions on hash tables. sxhash is intended for use where the pre-defined abstractions are insufficient. Its main intent is to allow the user a convenient means of implementing more complicated hashing paradigms than are provided through hash tables.

The hash codes returned by sxhash are not necessarily related to any hashing strategy used by any other function in Common Lisp.

For objects of types that equal compares with eq, item 3 requires that the hash-code be based on some immutable quality of the identity of the object. Another legitimate implementation technique would be to have sxhash assign (and cache) a random hash code for these objects, since there is no requirement that similar but non-eq objects have the same hash code.